It's not the carb, it's Triumph screws/fasteners in general. Don't get me started. Your best option if you haven't already is to pull the carbs, soak the screws in some PB Blaster overnight
Needle nose vise might work but you'll probably end up dremel tooling a nice slot in each and using a snug fit wide blade screwdriver. Be careful man I've seen the edges of the carb snap off with too much force. Obviously once you get these all removed order a set of the allen head screws from Fast Eddy or Brent at New Bonneville.
